Try setting the forcearray option - otherwise nested elements get transformed into attributes, as is happening in your example. Here's some code: 
#!/usr/local/bin/perl -w
use strict;
use XML::Simple;
local $/=undef; 
my $input=<DATA>;
my $xml=XMLin($input, 'forcearray' => 1);
$xml->{'fields'}->[0]{'field'}{$_}{'number'}->[0] += 10 for keys %{$xm
+l->{'fields'}->[0]{'field'}};
print XMLout($xml, 'rootname' => 'data');
__DATA__
<data>
  <fields>    
    <field name="foo">
      <number>2</number>
      <required>Y</required>
    </field>
    <field name="bar">
      <number>1</number>
      <required>N</required>
    </field>
  </fields>
</data>
_END__
<data>
  <fields name="field">
    <bar>
     <number>11</number>
     <required>N</required>
    </bar>
    <foo>
      <number>12</number>
      <required>Y</required>
    </foo>
  </fields>
</data>

[download]

Update: grantm beat me to the punch :). He's also using better options than me - my code mangles other parts of the XML structure. Better code is (only relevant lines shown): 

my $xml=XMLin($input, 'forcearray' => [('number','required')]);
$xml->{'fields'}{'field'}{$_}{'number'}->[0] += 10 for keys %{$xml->{'
+fields'}{'field'}};
print XMLout($xml, keyattr => {field => 'name'}, 'rootname' => 'data')
+;

[download]
Which actually works :)

CU
Robartes-

In reply to Re: Edit values in XML and Save? by robartes
in thread Edit values in XML and Save? by Cody Pendant

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